refactor vm

fix-vm/src/instructions/collections.rs

@@ -0,0 +1,189 @@
+use fix_error::Error;
+use gc_arena::Gc;
+use smallvec::SmallVec;
+
+use crate::{
+    AttrKeyData, AttrSet, BytecodeReader, List, NixString, OperandData, StepResult, Value,
+};
+
+impl<'gc> crate::Vm<'gc> {
+    #[inline(always)]
+    pub(crate) fn op_make_attrs(
+        &mut self,
+        ctx: &mut impl crate::VmContext,
+        reader: &mut BytecodeReader<'_>,
+        mc: &gc_arena::Mutation<'gc>,
+    ) -> StepResult<'gc> {
+        let count = reader.read_u32() as usize;
+        let mut entries: SmallVec<[AttrEntry; 4]> = SmallVec::with_capacity(count);
+        for _ in 0..count {
+            let key = reader.read_attr_key_data(ctx);
+            let val = reader.read_operand_data(ctx);
+            let _span_id = reader.read_u32();
+            entries.push(AttrEntry { key, val });
+        }
+        let mut kv: SmallVec<[(crate::StringId, Value); 4]> = SmallVec::with_capacity(count);
+        for entry in &entries {
+            let key_sid = match &entry.key {
+                AttrKeyData::Static(sid) => *sid,
+                AttrKeyData::Dynamic(op) => {
+                    let v = op.resolve(mc, self);
+                    v.as_inline::<crate::StringId>()
+                        .expect("dynamic attr key must be a string")
+                }
+            };
+            let val = entry.val.resolve(mc, self);
+            kv.push((key_sid, val));
+        }
+        kv.sort_by_key(|(k, _)| *k);
+        let attrs = Gc::new(mc, AttrSet::from_sorted_unchecked(kv));
+        self.push_stack(Value::new_gc(attrs));
+        StepResult::Continue
+    }
+
+    #[inline(always)]
+    pub(crate) fn op_make_empty_attrs(&mut self) -> StepResult<'gc> {
+        self.push_stack(self.empty_attrs);
+        StepResult::Continue
+    }
+
+    #[inline(always)]
+    pub(crate) fn op_select_static(
+        &mut self,
+        ctx: &mut impl crate::VmContext,
+        reader: &mut BytecodeReader<'_>,
+        mc: &gc_arena::Mutation<'gc>,
+    ) -> StepResult<'gc> {
+        let _span_id = reader.read_u32();
+        let key = reader.read_string_id();
+
+        if let Some(step) = self.try_force_resolved(0, reader.inst_start_pc(), mc) {
+            return step;
+        }
+
+        let attrs = self.peek_stack(0).restrict().expect("forced");
+        let Some(attrset) = attrs.as_gc::<AttrSet>() else {
+            return StepResult::Done(Err(Error::eval_error(
+                "value is not a set while a set was expected",
+            )));
+        };
+
+        match attrset.lookup(key) {
+            Some(v) => {
+                self.replace_stack(0, v);
+            }
+            None => {
+                loop {
+                    let byte = reader.bytecode()[reader.pc()];
+                    if byte == fix_codegen::Op::SelectStatic as u8 {
+                        reader.set_pc(reader.pc() + 1 + 4 + 4);
+                    } else if byte == fix_codegen::Op::SelectDynamic as u8 {
+                        reader.set_pc(reader.pc() + 1 + 4);
+                    } else if byte == fix_codegen::Op::JumpIfSelectSucceeded as u8 {
+                        reader.set_pc(reader.pc() + 1 + 4);
+                        let _ = self.pop_stack();
+                        break;
+                    } else {
+                        let name = ctx.resolve_string(key);
+                        return StepResult::Done(Err(Error::eval_error(format!(
+                            "attribute '{name}' missing"
+                        ))));
+                    }
+                }
+            }
+        }
+        StepResult::Continue
+    }
+
+    #[inline(always)]
+    pub(crate) fn op_select_dynamic(
+        &mut self,
+        ctx: &mut impl crate::VmContext,
+        reader: &mut BytecodeReader<'_>,
+        mc: &gc_arena::Mutation<'gc>,
+    ) -> StepResult<'gc> {
+        let _span_id = reader.read_u32();
+
+        if let Some(step) = self.try_force_resolved(0, reader.inst_start_pc(), mc) {
+            return step;
+        }
+        if let Some(step) = self.try_force_resolved(1, reader.inst_start_pc(), mc) {
+            return step;
+        }
+
+        let key_val = self.stack[self.stack.len() - 1]
+            .restrict()
+            .expect("dynamic key must be forced");
+        let key_sid = if let Some(sid) = key_val.as_inline::<crate::StringId>() {
+            sid
+        } else if let Some(ns) = key_val.as_gc::<NixString>() {
+            ctx.intern_string(ns.as_str())
+        } else {
+            return StepResult::Done(Err(Error::eval_error(
+                "dynamic select key must be a string",
+            )));
+        };
+
+        let attrset_val = self.stack[self.stack.len() - 2].restrict().expect("forced");
+        let Some(attrset) = attrset_val.as_gc::<AttrSet>() else {
+            return StepResult::Done(Err(Error::eval_error(
+                "value is not a set while a set was expected",
+            )));
+        };
+
+        match attrset.lookup(key_sid) {
+            Some(v) => {
+                self.stack.truncate(self.stack.len() - 2);
+                self.push_stack(v);
+            }
+            None => {
+                let name = ctx.resolve_string(key_sid);
+                return StepResult::Done(Err(Error::eval_error(format!(
+                    "attribute '{name}' missing"
+                ))));
+            }
+        }
+        StepResult::Continue
+    }
+
+    #[inline(always)]
+    pub(crate) fn op_jump_if_select_succeeded(&mut self, reader: &mut BytecodeReader<'_>) -> StepResult<'gc> {
+        let offset = reader.read_i32();
+        reader.set_pc(((reader.pc() as isize) + (offset as isize)) as usize);
+        StepResult::Continue
+    }
+
+    #[inline(always)]
+    pub(crate) fn op_has_attr(&mut self, reader: &mut BytecodeReader<'_>) -> StepResult<'gc> {
+        let _n = reader.read_u16() as usize;
+        todo!("HasAttr");
+    }
+
+    #[inline(always)]
+    pub(crate) fn op_make_list(
+        &mut self,
+        ctx: &mut impl crate::VmContext,
+        reader: &mut BytecodeReader<'_>,
+        mc: &gc_arena::Mutation<'gc>,
+    ) -> StepResult<'gc> {
+        let count = reader.read_u32() as usize;
+        let mut items: SmallVec<[Value; 4]> = SmallVec::with_capacity(count);
+        for _ in 0..count {
+            items.push(reader.read_operand_data(ctx).resolve(mc, self));
+        }
+        let list = Gc::new(mc, List { inner: items });
+        self.push_stack(Value::new_gc(list));
+        StepResult::Continue
+    }
+
+    #[inline(always)]
+    pub(crate) fn op_make_empty_list(&mut self) -> StepResult<'gc> {
+        self.push_stack(self.empty_list);
+        StepResult::Continue
+    }
+}
+
+pub(crate) struct AttrEntry {
+    pub(crate) key: AttrKeyData,
+    pub(crate) val: OperandData,
+}